HelloWorld.go

 package main

import "fmt"

// Função recursiva para calcular o fatorial de um número
func fatorial(n int) int {
	if n == 0 {
		return 1
	}
	return n * fatorial(n-1) // Chamada recursiva
}

func main() {
	// Valor fixo para simular a entrada do usuário
	numero := 5

	// Exibe o resultado do fatorial
	fmt.Printf("Fatorial de %d é %d\n", numero, fatorial(numero))
}

created 1 month ago by Caio

Go Online Compiler

Write, Run & Share Go code online using OneCompiler's Go online compiler for free. It's one of the robust, feature-rich online compilers for Go language, running on the latest version 1.10.2. Getting started with the OneCompiler's Go compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as GO and start coding.

Read inputs from stdin

OneCompiler's Go online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample Go program which takes name as input and prints hello message with your name.

package main
import "fmt"

func main() {
  var name string 
  fmt.Scanf("%s", &name) 
	fmt.Printf("Hello %s", name)
}

About Go

Go language is an open-source, statically typed programming language by Google. Go is highly recommended for creation of highly scalable and available web applications.

Some of the products developed using Go are Kubernetes, Docker, Dropbox, Infoblox etc.

Key Features

Fast compilation
Easy to write concurrent programs
Simple and concise syntax
Supports static linking
Opensource and huge community support.

Syntax help

Data Types

Data type	Description	Size	Range
uint8	8-bit unsigned integer	1 byte	0 to 255
int8	8-bit signed integer	1 byte	-128 to 127
int16	16-bit signed integer	2 bytes	-32768 to 32767
unit16	16-bit unsigned integer	2 bytes	0 to 65,535
int32	32-bit signed integer	4 bytes	-2,147,483,648 to 2,147,483,647
uint32	32-bit unsigned integer	4 bytes	0 to 4,294,967,295
int64	64-bit signed integer	8 bytes	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
uint64	64-bit unsigned integer	8 bytes	0 to 18,446,744,073,709,551,615
float32	32-bit signed floating point number	4 bytes	±1.5e-45 to ±3.4e38
float	64-bit signed floating point number	8 bytes	±5.0e-324 to ±1.7e308
string	sequence of immutable text
bool	Stores either true or false	1 byte	True or false

Variables

Variable is a name given to the storage area in order to manipulate them in our programs.

var varible-names datatype;

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition or set of conditions then If or IF-ELSE or Nested If-Elif-Else are used.

If

if(conditional-expression) {
   // code
}

If-Else

if(conditional-expression) {
   // code
} else {
   // code
}

Nested If-Else

if(conditional-expression) {
   // code
} else if(conditional-expression) {
   // code
} else {
   // code
}

2. For:

For loop is used to iterate a set of statements based on a condition.

for Initialization; Condition; Increment/decrement {  
  // code  
}

3. Switch:

Switch is an alternative to If-Else-If ladder.

switch conditional-expression {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
}

Note:

Go doesn't have while or do-while loops like in C.

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

func functionname(parameter-name type) returntype {  
 //code
}